%N a(n) = Pi(n)-Pi(sqrt(n)) + 1
%C a(n)=sum( d' dividing n, mu(d')*floor(n/d')) where each prime factor of d' is <=sqrt(n).
%C A well-known application of the principle of inclusion-exclusion used in sieve methods.
%C Number of numbers less than or equal to n and coprime to the product of the primes less than sqrt(n), i.e. to A104588(n). - _Lekraj Beedassy_, Mar 17 2005
%F a(n) = pi(n) - pi(sqrt(n)) + 1 = A000720(n) - A056811(n) + 1 = A056812(n) + 1.
%Y Cf. A000720, A056811.
%A _Benoit Cloitre_, Feb 16 2003
%E Edited by _N. J. A. Sloane_ at the suggestion of Andrew Plewe, Jun 12 2007